https://leetcode.cn/problems/group-anagrams/

class Solution {
public:
    vector<vector<string>> groupAnagrams(vector<string>& strs) {
        unordered_map<string,vector<string>> hash;
        for(auto & s:strs)
        {
            string tmp=s;
            sort(tmp.begin(),tmp.end());
            hash[tmp].push_back(s);
        }

        vector<vector<string>> ret;
        for(auto [x,y]:hash)
        {
            ret.push_back(y);
        }

        return ret;
    }
};